1. Field of the Invention
The present invention relates to a distributed processing system suitable for large scale distributed processing, and more particularly to a distributed processing system including a plurality of networks to which one or more computers are connected.
2. Description of the Prior Art
Recently, a distributed processing has been used in a variety of fields. In order to realize a distributed processing with high efficiency, it is necessary to make efficient management and utilization of resources on each computer and to provide communication between computers with high efficiency. Some systems have hitherto been proposed for such a purpose.
There is known a distributed processing system, as disclosed by, for example, JP-A-(SHO)61267859, which is provided with a process management table in which the state, identification number, node address, etc. of processes on each node are registered. Upon transmission of a message, a supervisor process makes reference to the process management table to transmit the message, thereby allowing message transmission with high efficiency.
There is also known a distributed resource accessing method, as disclosed by, for example, JP-A(HEI)1-166158, in which management information for virtual resource management of making resources on distributed on computers look like resources on one computer is held on one computer in order to make efficient utilization and management of a large amount of resources, and access to the distributed resources is made using virtual identification means which has the same management structure on all the computers.
In many methods for forming a high-efficiency distributed processing system in a distributed processing environment, there is used a system in which a management table for making unitary management of various resources on computers in the distributed processing environment is prepared and the utilization of the resources is made using information of the management table. In many cases, such unitary information management is especially used in order to realize the transparency (or transmissibility) of the distributed processing environment. More particularly, there is known a system which makes resources distributed on computers in a distributed environment look like resources existing on one computer (see, for example, JP-A-(HEI)1-166158 and JP-A-(HEI)1-166159). In this system, information for unitary management is held in one computer in order to realize a virtual resource management, thereby making it possible to access a remote distributed resource by use of virtual identification means which has the same management structure on all the computers.
However, the above prior art discloses a system which manages a process at each computer or a system which manages resources of the whole of the system in a unified manner at one location. Therefore, the prior art involves a problem wherein no consideration is given to efficient management of a large scale distributed processing system having a large amount of hardware and software distributed over a wide area and a problem that detailed information concerning system construction is required for realization of an efficient processing in the case of a large scale system. Further, especially, when a user programs the recognition of information concerning individual objects, a precondition is that the user is well aware of the hardware/software construction of the whole system. However, in the case of a wide area and large scale distributed processing system, this precondition itself is very difficult.
The term "object" means an application program, a process, a program module, a file, a database and other resource in a distributed environment, and the processing is generally activated by receiving a message. The processing is advanced with message passing between objects.